Wao 750-880 RS485 problem

loopin3 · Mar 18, 2014

hi all , i have a couple controller wago with 750-653/003-000 RS485 module. I have connected on the rs485 4 modbus ADC with 8 channel. I want read 8 register per ADC. I wrote a function block that do this with modbus_extended_master, part of wago library. When i call the function block from the main programit work for first instance to read a someone ADC. when i want read 2 ADC the second instance dosent work.. why i cant read with second instance?

tank you in advance.

loopin3 · Mar 18, 2014

I look in the second instance of modbus FB the error 5 -> serial port already open.
when i call a fb how can close the serial port and call another instance of fb?
thanks.

shooter · Mar 18, 2014

can you please send me the library, and i will have a look if it is changeable
otherwise find how to close the comms, however this takes time and is not needed
the error comes because the FB wants to open a communication, but it is already open.
http://www.wago.com/wagoweb/documentation/app_note/libdoku/ml01101e.pdf is a example how to do it.
ready is on until comms are ended. then you can false the start input and the comms will close.

another way is to use oscat library at www.oscat.de (yes it is english
go to downloadmanager.

loopin3 · Mar 19, 2014

in the oscat cat library i can find the modbus library?
I send you a wago library but if enable is false the comm doesnt close !

loopin3 · Mar 19, 2014

ok a FB with enable= false close the com port but if i call fb after fb return error 12 0x0C Bus module could not be initialised.

shooter · Mar 19, 2014

within oscat network you can find a lot of function blocks to help you, they are not vendor specific, however they are easy readable and you can change them.

loopin3 · Mar 19, 2014

in the oscat network library dosent have a mod bus master over serial line :-(

shooter · Mar 19, 2014

it all takes time, so you will have to wait, until comms are empty and stopped.

Wao 750-880 RS485 problem

loopin3

Member

loopin3

Member

shooter

Member

loopin3

Member

loopin3

Member

shooter

Member

loopin3

Member

shooter

Member

Similar Topics